JP5295858B2 - Electromagnetic actuator, electromagnetically operated switchgear using the same, and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change velocity of a switching operation efficiently, in an electromagnetic actuator biased by a spring and a switching device of a solenoid operation type with the actuator mounted. <P>SOLUTION: The electromagnetic actuator 3 includes a stator 31, a rotor 32 arranged while being reciprocally moved in a space of the stator 31, an open spring 33 biasing the rotor 32 to a direction separating from the stator 31, a plurality of driving coils 34 arranged along a displacing direction of the rotor 32 in the space of the stator 31 and driving the rotor 32, a driving circuit 7 supplying excitation current to each driving coil 34, and a permanent magnet 35 adsorbing and retaining the rotor 32 on the stator 31 side. By selecting an exciting direction of each driving coil 34 and an exciting driving coil 34, a displacing direction and velocity of the rotor 32 are changed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electromagnetic actuator, a switching device such as a circuit breaker and a switch equipped with the electromagnetic actuator, and a control method thereof.

In recent years, it has been proposed to employ an electromagnetic actuator with excellent operation controllability instead of the current hydraulic operation mechanism and spring operation mechanism as the operation mechanism of switchgears such as circuit breakers and switches. The structure of a bistable type electromagnetic actuator is shown (for example, refer patent document 1).
Further, in a bistable type electromagnetic actuator, the response and speed of the opening / closing operation are changed by exciting two drive coils at different timings (see, for example, Patent Document 2).

EP 0 721 650 B1 publication (FIG. 1 etc.) GB 2 299 896 A (FIG. 3 etc.)

In general, since the breaking performance of a circuit breaker or the like depends on the opening speed of the contact, the operation mechanism such as the circuit breaker is required to have an operation speed that satisfies the necessary breaking performance. And the opening speed required for interruption | blocking changes with the state and conditions (electrical conditions, such as a circuit impedance and a circuit voltage) of the main circuit to which a circuit breaker etc. are connected. However, current operating mechanisms are generally designed for the fastest opening speed required, in which case they operate at excessive speed even during normal opening and closing operations where high speed opening is not required. It will be. If the switching operation is fast, a load is repeatedly applied to the structural member of the circuit breaker and its operating mechanism, resulting in a problem that the mechanical life (number of switching operations) of the circuit breaker decreases due to a decrease in strength of the structural member due to fatigue. is there.
In particular, in an extra-high voltage or higher voltage class circuit breaker or the like, high speed is required by the opening speed in preparation for a serious failure such as a large current interruption such as a short circuit accident. However, the occurrence frequency of serious faults is small, and light faults that do not require high-speed opening and normal load current switching and no-load switching due to normal switching are almost all. Therefore, designing the breaking performance for the fastest opening speed required is very inefficient.
By the way, in a circuit breaker or the like of an extra high voltage, a long contact stroke is required to ensure a withstand voltage performance in an open state. And in order to implement | achieve high-speed opening with a circuit breaker with a long contact stroke, it is common to use an open spring for the electromagnetic actuator as an operation mechanism. If the opening speed can be selected in an electromagnetic actuator using an open spring in this way, mechanical stress on the electromagnetic actuator and a circuit breaker using the electromagnetic actuator can be reduced, and a life extension can be expected.
Patent Document 2 describes changing the responsiveness and speed of the opening / closing operation in a bistable type electromagnetic actuator. However, since it is not a spring-biased configuration, it is the same as Patent Document 2. In the configuration, the opening and closing speed of the electromagnetic actuator biased by the spring cannot be changed.

  The present invention has been made to solve the above-described problems. In an electromagnetic actuator biased by a spring and an electromagnetically operated switching device equipped with the electromagnetic actuator, the speed of the switching operation is changed efficiently. The purpose is to let you.

An electromagnetic actuator according to the present invention is of an electromagnetic operation type that drives in a reciprocating manner between two positions of an opening and a closing, and is arranged in a reciprocating manner in a stator and an inner space of the stator. A plurality of movers, a release spring that biases the mover in a direction away from the stator, and a plurality of drives for driving the mover arranged in the inner space of the stator along the moving direction of the mover. A coil, a drive circuit for supplying an excitation current to each drive coil, and a permanent magnet for attracting and holding the mover on the stator side are provided. By selecting the excitation direction and the excitation coil to be excited from each of the drive coils, the magnetic flux generated by the drive coil is made larger during the low-speed release operation than during the high-speed release operation, so that the stator and the movable It controls to increase the magnetic attractive force with the child .

An electromagnetically operated switchgear according to the present invention is disposed on a control rod, a contact pair consisting of a fixed contact and a movable contact, which can be contacted and separated, an electromagnetic actuator which opens and closes the contact pair via the control rod, and And an insulating body that insulates the contact pair from the electromagnetic actuator, and a contact pressure spring that is disposed on the operating rod and applies a contact load to the contact pair, and opens and closes the main circuit. The electromagnetic actuator includes a stator, a mover arranged in a reciprocating manner in the inner space of the stator, an open spring that biases the mover in a direction away from the stator, and an inner space of the stator. A plurality of drive coils arranged along the moving direction of the mover for driving the mover, a drive circuit for supplying an excitation current to each drive coil, and a permanent magnet for attracting and holding the mover on the stator side And. By selecting the excitation direction and the excitation coil to be excited from each of the drive coils, the magnetic flux generated by the drive coil is made larger during the low-speed release operation than during the high-speed release operation, so that the stator and the movable It controls to increase the magnetic attractive force with the child .

Also, the control method of the electromagnetically operated switchgear according to the present invention is arranged in a reciprocable manner in the inner space of the stator and the pair of contacts that can be separated from each other, comprising a stationary contact and a movable contact. A mover, an open spring that urges the mover in a direction away from the stator, and a plurality of drive coils arranged in the inner space of the stator along the moving direction of the mover to drive the mover And an electromagnetic operation type driving circuit for reciprocating between two positions of opening and closing, including a driving circuit for supplying an exciting current to each driving coil and a permanent magnet for attracting and holding the mover on the stator side . This is a method for controlling an electromagnetically operated switching device for opening and closing a main circuit comprising an electromagnetic actuator and an operating rod for connecting a contact pair and the electromagnetic actuator. Then, by selecting the excitation direction and the excitation coil to be excited from among the respective drive coils, the magnetic flux generated by the drive coil is made larger during the low speed release operation than during the high speed release operation, and the stator and the above Control is performed to increase the magnetic attractive force with the mover .

The electromagnetic actuator according to the present invention includes an opening spring that separates the mover from the stator, so that a high-speed opening operation can be realized even in the case of a long stroke, and an excitation direction and excitation are provided from among the driving coils by including a plurality of driving coils. Since the drive coil to be moved is selected and the moving direction and moving speed of the mover are changed, the opening and closing operation can be performed according to the situation . By controlling to increase the magnetic attractive force between the stator and the mover by increasing the magnetic flux, the opening operation speed can be controlled to be slow, so that the mechanical life of the electromagnetic actuator can be increased.

The electromagnetically operated switchgear according to the present invention is equipped with an electromagnetic actuator having a plurality of drive coils and an open spring that separates the mover from the stator. In addition to realizing the opening operation, the contact direction of the switchgear is opened and closed by selecting the excitation direction and the drive coil to be excited from among each drive coil and changing the moving direction and moving speed of the mover. It can be opened and closed, and in particular, the magnetic flux generated by the drive coil is controlled to increase the magnetic attractive force between the stator and the mover by increasing the magnetic flux during the low-speed opening operation than during the high-speed opening operation. By doing so, since the opening operation speed can be controlled to be slow, the mechanical life of the switchgear can be increased.

According to another aspect of the present invention, there is provided a control method for an electromagnetically operated switchgear comprising a release spring for separating a mover from a stator and an electromagnetic actuator having a plurality of drive coils. The opening spring can realize a high-speed opening operation even in the case of a long stroke, and by selecting the excitation direction and the excitation coil to be excited from each drive coil and changing the moving direction and moving speed of the mover, Opening and closing operation according to the situation can be performed to open and close the contact pair, and in particular, the magnetic flux generated by the drive coil is made larger in the low speed opening operation than in the high speed opening operation, so that the stator and the mover By controlling so as to increase the magnetic attractive force, the opening operation speed can be controlled to be slow, so that the mechanical life of the switchgear can be increased.

It is a schematic diagram for demonstrating the structure of the circuit breaker in Embodiment 1 of this invention, and shows the case of an open state. It is a schematic diagram for demonstrating the structure of the circuit breaker in Embodiment 1 of this invention, and shows the case of a closing state. It is a circuit diagram which shows the drive circuit in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a graph which shows the relationship between the force which acts on the needle | mover of the electromagnetic actuator in Embodiment 1 of this invention, and a stroke position. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a graph which shows the relationship between the force which acts on the needle | mover of the electromagnetic actuator in Embodiment 1 of this invention, and a stroke position. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a schematic diagram explaining operation | movement of the electromagnetic actuator in Embodiment 1 of this invention. It is a graph which shows the relationship between the force which acts on the needle | mover of the electromagnetic actuator in Embodiment 1 of this invention, and a stroke position. It is a circuit diagram which shows the drive circuit in Embodiment 2 of this invention. It is a schematic diagram for demonstrating the structure of the electromagnetic actuator in Embodiment 3 of this invention. It is a circuit diagram which shows a part of drive circuit in Embodiment 3 of this invention. It is a circuit diagram which shows a part of drive circuit in Embodiment 3 of this invention. It is a circuit diagram which shows the drive circuit in another example of Embodiment 3 of this invention.

Embodiment 1 FIG.
1 and 2 are schematic views for explaining the configuration of a circuit breaker as a switchgear according to Embodiment 1 of the present invention. FIG. 1 shows an open state where the contact pair of the circuit breaker is open, and FIG. 2 shows a case where the contact pair of the circuit breaker is closed.
As shown in FIGS. 1 and 2, the circuit breaker 1 is configured by connecting a vacuum valve 2 and an electromagnetic actuator 3 by an operating rod 6 via an insulator 4 and a contact pressure spring 5.
The vacuum valve 2 is provided with a pair of contactable contacts that are composed of a fixed contact 22 and a movable contact 23 in a cylindrical insulating container 21 whose interior is kept in a vacuum.

  The electromagnetic actuator 3 has a stator 31 made of a magnetic material, and a mover 32 arranged in a reciprocable manner in the inner space of the stator 31. In the first embodiment, the stator 31 is composed of an upper portion 31A (moving element 32 opening direction side), a lower portion 31B (moving element 32 loading direction side), and a side portion 31C, and has a substantially rectangular cross section inside. Is forming. An opening 31D into which the mover 32 can be inserted is provided in the upper part 31A, and a through hole 31E through which the operation rod 6 passes is provided in the lower part 31B. An open spring 33 is provided between the upper portion 31A and the mover 32 to urge the mover 32 in a direction away from the stator 31 (upward in the drawing). In the inner space of the stator 31, a plurality of drive coils 34 that are arranged along the moving direction of the mover 32 and drive the mover 32 are provided. In the first embodiment, each drive coil 34 is disposed at two locations on the upper 31A side and the lower 31B side of the inner space of the stator 31, and the operation rod 6 and the mover 32 are located inside each drive coil 34A, 34B. It is comprised so that it may penetrate. The drive coil disposed on the upper 31A side is referred to as a first drive coil 34A, and the drive coil disposed on the lower 31B side is referred to as a second drive coil 34B. A magnetic pole portion 35 is provided between the first and second drive coils 34A and 34B so as to protrude from the side portion 31C of the stator 31. The opening 31D of the stator 31 includes a pair of permanent magnets 36 that attract and hold the mover 32 toward the lower portion 31B.

The operating rod 6 has one end fixed to the movable contact 23 and the other end fixed to the mover 32, and connects the vacuum valve 2 and the electromagnetic actuator 3. A contact pair consisting of 22 opens and closes.
An insulator 4 and a contact pressure spring 5 are disposed between the vacuum valve 2 of the operation rod 6 and the electromagnetic actuator 3. In the first embodiment, the vacuum valve 2, the insulator 4, the contact pressure spring 5, Each component is fixed on the same axis in the order of the electromagnetic actuator 3. The insulator 4 is for insulating the vacuum valve 2 and the electromagnetic actuator 3, and the contact pressure spring 5 is for applying a contact load to a contact pair composed of a fixed contact 22 and a movable contact 23.

  The drive coils 34A and 34B are connected to a drive circuit 7 that supplies an exciting current to drive the drive coils 34A and 34B. This drive circuit 7 is shown in FIG. As shown in the figure, the drive circuit 7 includes capacitors 71A and 71B, discharge switches 72A and 72B, changeover switches 73a, 73b, 74a, 74b, 75a and 75b, freewheeling diodes 76A and 76B, a resistor 77, and a drive coil 34A. , 34B. The current discharged from the charged capacitors 71A and 71B excites the drive coils 34A and 34B via the discharge switches 72A and 72B and the changeover switches 73a, 73b, 74a, 74b, 75a, and 75b. The resistor 77 is a resistor for limiting the current flowing from the capacitor 71B to the drive coils 34A and 34B, and is connected to the positive terminal side of the capacitor 71B. Further, switches 78A and 78B are connected in series to the freewheeling diodes 76A and 76B, respectively, to control the current to the freewheeling diodes 76A and 76B.

In the first embodiment, the operation of the circuit breaker 1 includes a high-speed opening operation when a major failure occurs in the main circuit to which the circuit breaker 1 is connected, a case where a minor failure occurs in the main circuit, or normal There are a low-speed opening operation in the case of opening and closing, and a closing operation for returning the main circuit that has been blocked by the opening operation.
Whether the opening operation is performed at a high speed or a low speed among the operations of the circuit breaker 1 is determined by the control circuit 8 connected to the drive circuit 7 (see FIGS. 1 and 2). The control circuit 8 performs a high-speed operation or a low-speed operation based on an output of a measurement result obtained by measurement means (not shown) that measures a current and voltage of a main circuit (not shown) to which the circuit breaker 1 is connected. It is determined whether to perform an operation, and an operation command is sent to the drive circuit 7. Hereinafter, each operation of the circuit breaker 1 will be described.

  First, referring to FIGS. 4 to 9, a closing operation for returning the main circuit will be described. The making operation is an operation for shifting from the open state (the state shown in FIG. 1) to the making state (the state shown in FIG. 2). 4 to 7 and FIG. 9 are diagrams for explaining the operation of the electromagnetic actuator 3, and FIG. 8 shows the relationship between the force acting on the mover 32 and the stroke position.

First, the state of the electromagnetic actuator 3 in the open state will be described with reference to FIG. When stable in the open state, since the discharge switches 72A and 72B are OFF and neither of the drive coils 34A and 34B is excited, no magnetic flux is generated from the drive coils 34A and 34B. The permanent magnet 36 generates a magnetic flux Φpm (indicated by a dotted arrow in the figure). However, since the distance between the mover 32 and the lower portion 31B of the stator 31 is long and the magnetic gap is large, the amount of magnetic flux is very small. For this reason, there is almost no attracting force which attracts the mover 32 to the lower portion 31B side of the stator 31 by the magnetic flux Φpm, and does not affect the movement of the mover 32. Therefore, the position of the mover 32 is stable at the open position by the upward biasing force Fo of the open spring 33.
Each switch of the drive circuit 7 is set in preparation for the next closing operation after the end of the previous opening operation, the change-over switches 73a, 73b, 74a, 74b and the switch 78A are ON, and the change-over switches 75a, 75b and the switch 78B are OFF. It is a state.

When the closing operation is started in the open state as described above, the discharge switch 72A of the drive circuit 7 is turned on by the operation command. As a result, a current is discharged from the charged capacitor 71 </ b> A, and the drive coils 34 </ b> A and 34 </ b> B are excited in the same direction (forward direction) as the permanent magnet 36. A magnetic flux Φc (shown by a solid arrow in the figure) as shown in FIG. 5 is generated around the drive coils 34A and 34B, and this magnetic flux Φc is combined with a magnetic flux Φpm (shown by a dotted arrow in the figure) by the permanent magnet 36. Aspirate 32. If the magnetic attractive force acting on the movable element 32 by both magnetic fluxes Φc and Φpm at this time is Fem, the magnetic attractive force Fem becomes larger than the urging force Fo upward of the opening spring 33, so that the movable element 32 is fixed to the stator 31. Begins to move in the lower 31B direction.
As the mover 32 moves, the biasing force Fo of the release spring 33 increases. When the mover 32 moves to a predetermined position, an upward biasing force Fw by the contact pressure spring 5 is also applied. However, when the distance from the lower portion 31B of the stator 31 is reduced as the mover 32 moves, the magnetic gap is shortened, so that the amount of magnetic flux due to the magnetic fluxes Φc and Φpm increases and the magnetic attractive force Fem also increases. For this reason, as shown in FIG. 8 to be described later, at any position from the open position to the closing position, the magnetic attractive force Fem is more than the sum of the biasing forces Fo and Fw of the open spring 33 and the contact spring 5. growing. Accordingly, the release spring 33 and the contact pressure spring 5 are compressed, and the movable element 32 moves to a position where it comes into contact with the lower portion 31B (loading position) as shown in FIG.
The amount of magnetic flux Φpm generated by the permanent magnet 36 is smaller than the amount of magnetic flux Φc generated by the drive coils 34A and 34B. In particular, when the magnetic gap is large, the magnetic flux Φpm of the permanent magnet 36 is used to move the mover 32. There is no effect.

  Next, when the mover 32 moves to the closing position, the discharge switch 72A and the switch 78A of the drive circuit 7 are turned off, and excitation to the drive coils 34A and 34B is stopped. Accordingly, no magnetic flux is generated from each of the drive coils 34A and 34B, and only the magnetic flux Φpm by the permanent magnet 36 is generated as shown in FIG. At this time, the mover 32 and the lower part 31B are in contact with each other, and there is no magnetic gap in the magnetic path. (Suction force) is larger than the sum of the urging forces Fo and Fw of the release spring 33 and the contact pressure spring 5. Accordingly, even when the excitation of the drive coils 34A and 34B is stopped, the mover 32 is attracted and held on the lower 31B side of the stator 31.

FIG. 8 shows the relationship between the force acting on the mover 32 and the stroke position in a state where both the drive coils 34A and 34B are excited in the same direction as the permanent magnet 36 during the closing operation.
The horizontal axis indicates the stroke position of the mover 32, the right side being the open position and the left side being the closing position. The vertical axis represents the force acting on the mover 32, and shows the magnetic attractive force and the biasing force by the spring.
The urging force by the spring is represented by the sum of the urging force Fo of the opening spring 33 and the urging force Fw of the contact pressure spring 5. In the opened position, the urging force of the spring acting on the movable element 32 is only the urging force Fo by the opening spring 33. However, since the urging force Fw of the contact pressure spring 5 is applied from a predetermined position, a two-stage broken line as shown in the figure. become.
As the magnetic attraction force Fem approaches the closing position, the magnetic gap between the mover 32 and the lower portion 31B of the stator 31 is shortened, and thus the magnetic attraction force Fem increases. Therefore, when the stroke is long, the magnetic attractive force is reduced. However, in the first embodiment, the presence of the magnetic pole portion 35 forms a magnetic path that flows from the lower portion 31B to the mover 32 via the magnetic pole portion 35 as shown in FIG. Even at the position where the lower portion 31B is separated, the magnetic gap is shortened, and the magnetic attractive force Fem temporarily increases. The magnetic attractive force Fem has a curve as shown in FIG. 8, and has a high magnetic attractive force (convex portion) even in the vicinity of the open position.

  When the discharge switch 72A and the switch 78A of the drive circuit 7 are turned off and the closing operation is completed, the switches of the drive circuit 7 are prepared for the next opening operation, the changeover switches 75a and 75b and the switch 78B are turned on, and the changeover switches 73a and 73b. , 74a, 74b and switch 78A are set to OFF.

  Next, with reference to FIGS. 9 to 11, a high-speed opening operation when a major failure or the like occurs in the main circuit will be described. The opening operation is an operation for shifting from the input state (the state shown in FIG. 2) to the open state (the state shown in FIG. 1). 9 and 10 are diagrams for explaining the operation of the electromagnetic actuator 3, and FIG. 11 shows the relationship between the force acting on the mover 32 and the stroke position in the high-speed opening operation.

The state of the electromagnetic actuator 3 when the circuit breaker 1 is stable in the on state as shown in FIG. 2 is as described in FIG. The discharge switches 72A and 72B are OFF, and the drive coils 34A and 34B are not excited. The mover 32 is attracted and held on the lower portion 31B of the stator 31 by the magnetic flux Φpm generated by the permanent magnet 36 and is stable.
As described above, each switch of the drive circuit 7 is set in preparation for the opening operation after the previous closing operation is completed. The changeover switches 75a, 75b and the switch 78B are ON, and the changeover switches 73a, 73b, 74a, 74b and the switch 78A are turned on. Is in an OFF state.

When the opening operation is started in the above-described input state, first, the control circuit 8 determines whether to perform a high speed operation or a low speed operation, and sends an operation command to the drive circuit 7. In the case of high speed operation, the discharge switch 72B of the drive circuit 7 is turned on by an operation command. As a result, a current is discharged from the charged capacitor 71 </ b> B, and the second drive coil 34 </ b> B is excited in the opposite direction to the permanent magnet 36.
As shown in FIG. 9, the magnetic flux Φc1 (indicated by the solid line arrow in the figure) generated by the second drive coil 34B is mainly the magnetic flux Φpm (permanent magnet 36 passing through the lower part 31B, the side part 31C, and the magnetic pole part 35). A small loop magnetic path is formed in the opposite direction to that indicated by a dotted arrow in the figure. The magnetic flux Φc1 cancels the magnetic flux Φpm, and the magnetic attractive force Fem by the magnetic flux Φc1 and the magnetic flux Φpm becomes smaller than the sum of the urging forces Fo and Fw of the release spring 33 and the contact pressure spring 5. Then, as shown in FIG. 10, the mover 32 moves in the direction of the upper portion 31 </ b> A of the stator 31. In particular, in the state shown in FIG. 10 where the magnetic gap is large, the magnetic flux Φpm by the permanent magnet 36 is very small and does not affect the movement of the mover 32.

The opening speed will be described with reference to FIG.
As described above, since only the second drive coil 34B is reversely excited in the high-speed opening operation, the magnetic flux Φc1 generated by the second drive coil 34B is mainly a small loop magnetic field that passes through the lower part 31B, the side part 31C, and the magnetic pole part 35. Form a road. The magnetic flux Φc1 acts to attract the mover 32 when the mover 32 moves away from the lower part 31B. However, as shown in FIG. 10, the mover 32 moves to the open position side of the magnetic pole portion 35 and is a small loop. If it is away from the magnetic path, the attractive force by the magnetic flux Φc1 does not act on the mover 32. Therefore, as shown in FIG. 11, the magnetic attraction force Fem that attracts the mover 32 rapidly decreases. The mover 32 moves at a speed corresponding to an energy difference (shaded portion in the figure) between the spring biasing force (the sum of the biasing force Fo of the release spring 33 and the biasing force Fw of the contact pressure spring) and the magnetic attractive force Fem. Since the energy difference increases as the magnetic attractive force rapidly decreases, the mover 32 opens at a high speed.
Note that the magnetic flux Φc1 generated by the second drive coil 34B hardly flows through the path of the large loop passing through the lower part 31B, the side part 31C, and the upper part 31A, and mainly forms a magnetic path of the small loop. This is because the magnetic resistance is short and small.

When the mover 32 moves to the open position in this way, the discharge switch 72B and the switch 78B of the drive circuit 7 are turned off, and the excitation of the second drive coil 34B is stopped. As described with reference to FIG. 4, even when the excitation of the second drive coil 34 </ b> B is stopped, the movable element 32 is stabilized at the open position by the urging force Fo of the open spring 33.
Thereafter, each switch of the drive circuit 7 is set for the next turning-on operation, and the changeover switches 73a, 73b, 74a, 74b and the switch 78A are set to ON, and the changeover switches 75a, 75b and the switch 78B are set to OFF.

  During the closing operation, a magnetic attraction force larger than the urging force of the opening spring 33 and the contact spring 5 is required to move the mover 32 (see FIG. 8), but during the opening operation, the opening spring 33 and The mover 32 is moved by using a magnetic attractive force smaller than the biasing force of the contact spring 5 (see FIG. 11). Therefore, in order to obtain a desired magnetic attraction force during the opening operation, a resistor 77 is provided in the drive circuit 7 (see FIG. 3) to limit the current flowing through the second drive coil 34B.

  Next, with reference to FIGS. 12 to 14, a low-speed opening operation in the case where a minor failure or the like occurs in the main circuit or in a normal opening / closing will be described. 12 and 13 are diagrams for explaining the operation of the electromagnetic actuator 3, and FIG. 14 shows the relationship between the force acting on the mover 32 and the stroke position.

The state of the electromagnetic actuator 3 when the circuit breaker 1 is stable in the on state as shown in FIG. 2 is as described in FIG. The discharge switches 72A and 72B are OFF, and the drive coils 34A and 34B are not excited. The mover 32 is attracted and held on the lower portion 31B of the stator 31 by the magnetic flux Φpm generated by the permanent magnet 36 and is stable.
As described above, each switch of the drive circuit 7 is set in preparation for the opening operation after the previous closing operation is completed. The changeover switches 75a, 75b and the switch 78B are ON, and the changeover switches 73a, 73b, 74a, 74b and the switch 78A are turned on. Is in an OFF state.

When the opening operation is started in the above-described input state, first, the control circuit 8 determines whether to perform a high speed operation or a low speed operation, and sends an operation command to the drive circuit 7. Each switch of the drive circuit 7 set after the end of the previous closing operation is provided for a high-speed opening operation in which only the second drive coil 34B is reversely excited. Therefore, when it is determined that the low-speed operation is to be performed, the changeover switches 74a and 74b of the drive circuit 7 are first turned on by the operation command from the control circuit 8, and then the discharge switch 72B is turned on. As a result, a current is discharged from the charged capacitor 71B, and the first and second drive coils 34A, 34B are excited in the opposite direction to the permanent magnet 36.
As shown in FIG. 12, the magnetic flux Φc2 (indicated by solid arrows in the figure) generated by the first and second drive coils 34A and 34B is a magnetic flux generated by the permanent magnet 36 passing through the lower part 31B, the side part 31C, and the upper part 31A. A large loop magnetic path opposite to Φpm (indicated by a dotted arrow in the figure) is formed. The magnetic flux Φc2 cancels the magnetic flux Φpm, and the magnetic attractive force Fem by the magnetic flux Φc2 and the magnetic flux Φpm becomes smaller than the sum of the biasing forces Fo and Fw of the release spring 33 and the contact spring 5. Then, as shown in FIG. 13, the mover 32 moves toward the upper portion 31 </ b> A of the stator 31. In particular, in the state shown in FIG. 13 where the magnetic gap is large, the magnetic flux Φpm by the permanent magnet 36 is very small and does not affect the movement of the mover 32.

The opening speed will be described with reference to FIG.
As described above, since both the first and second drive coils 34A and 34B are reversely excited in the low speed opening operation, the magnetic flux Φc2 generated thereby is a large loop magnetic path passing through the lower part 31B, the side part 31C, and the upper part 31A. Form. When the mover 32 moves away from the lower portion 31B, the magnetic flux Φc2 acts so that the magnetic flux Φc2 attracts the mover 32 until the mover 32 reaches the open position. Further, when the magnetic path is formed by the magnetic flux Φc2 flowing from the mover 32 to the lower portion 31B via the magnetic pole portion 35 as shown in FIG. 13 due to the presence of the magnetic pole portion 35, the mover 32 and the lower portion 31B are formed. Even at a position away from each other, the magnetic gap is shortened, and the magnetic attractive force Fem temporarily increases.
For this reason, as shown in FIG. 14, the magnetic attractive force Fem for attracting the mover 32 does not rapidly decrease, and becomes a curve that gradually decreases compared to the case of FIG. When the magnetic attractive force is gradually reduced, the energy difference (shaded portion in the figure) between the spring biasing force (the sum of the biasing force Fo of the opening spring 33 and the biasing force Fw of the contact pressure spring) and the magnetic attractive force Fem is small. Therefore, the mover 32 opens at a low speed.
Further, only the second drive coil 34B is reversely excited in the case of the high-speed opening operation, and both the first and second drive coils 34A and 34B are reversely excited in the case of the low-speed opening operation. That is, the magnetic flux Φc1 in the case of only the second drive coil 34B is smaller than the magnetic flux Φc2 of both the drive coils 34A and 34B. Therefore, the magnetic attractive force Fem can be differentiated between high speed and low speed. As a result, the energy difference between the magnetic attractive force Fem and the spring biasing force can be adjusted to change the moving speed of the mover 32.
The moving speed of the mover can be set to a desired value by changing the resistance and the number of turns of each of the drive coils 34A and 34B to adjust the energy difference between the magnetic attractive force Fem and the spring biasing force.

When the mover 32 moves to the open position in this way, the discharge switch 72B and the switch 78B of the drive circuit 7 are turned off, and the excitation of the first and second drive coils 34A and 34B is stopped. As described with reference to FIG. 4, even when the excitation of the second drive coil 34 </ b> B is stopped, the movable element 32 is stabilized at the open position by the urging force Fo of the open spring 33.
Thereafter, each switch of the drive circuit 7 is set for the next turning-on operation, and the changeover switches 73a, 73b, 74a, 74b and the switch 78A are set to ON, and the changeover switches 75a, 75b and the switch 78B are set to OFF.

  As described above, during the closing operation, a magnetic attraction force larger than the urging force of the opening spring 33 and the contact spring 5 is required to move the mover 32 (see FIG. 8). The mover 32 is moved by using a magnetic attractive force smaller than the urging force of the spring 33 and the contact pressure spring 5 (see FIG. 11). Therefore, in order to obtain a desired magnetic attraction force during the opening operation, a resistor 77 is provided in the drive circuit 7 (see FIG. 3) to limit the current flowing through the first and second drive coils 34A and 34B.

As described above, according to the first embodiment, a plurality of drive coils are provided in an electromagnetic actuator that can realize a high-speed opening operation even in the case of a long stroke by providing an opening spring that separates the mover from the stator. Since the moving direction of the mover can be changed by selecting the excitation direction of each driving coil and the driving coil to be excited, the switching operation according to the situation can be performed, the electromagnetic actuator and the circuit breaker equipped with this The mechanical life of can be increased.
In addition, since the magnetic pole portion is disposed between adjacent drive coils, a small loop magnetic path passing through the magnetic pole portion can be formed by selecting the drive coil to be excited. Thereby, the moving speed of the mover can be changed more efficiently. Further, since the magnetic flux flows through the magnetic pole portion, it is possible to suppress a decrease in magnetic attractive force due to the magnetic gap between the mover and the stator even in the case of a long stroke. For this reason, it is possible to reduce the size of the electromagnetic actuator and the capacity of the drive power supply.
Whether to perform high speed operation or low speed operation during the opening operation is determined by the control circuit based on the measurement result of the current or voltage of the main circuit connected to the circuit breaker equipped with the electromagnetic actuator, and is excited by this A drive coil is selected. For this reason, the mover can be moved at an appropriate speed according to the situation of the main circuit. Thereby, unnecessary high-speed switching operation can be eliminated, and the mechanical life of the circuit breaker and the like can be improved.

The shape of the stator is not limited to the shape of the first embodiment. For example, the stator has a cylindrical shape having an opening on one end side, and the end of the mover can be inserted and removed from the opening. There may be.
Further, the number of drive coils provided in the stator is not limited to two, and three or more drive coils are provided along the moving direction of the mover in accordance with the stroke length of the electromagnetic actuator. May be. In this case, for example, all the drive coils are excited in the forward direction during the closing operation, only the drive coil arranged at the end of the closing direction of the mover is reversely excited during the high-speed opening operation, and the mover is moved during the low-speed opening operation. The moving direction and moving speed of the mover are adjusted by reverse-exciting two or more driving coils including the driving coil arranged at the end of the closing direction.
In the first embodiment, the moving speed of the mover 32 is adjusted only during the opening operation. However, even during the closing operation, the magnetic attraction force is adjusted by selecting the driving coil to be excited, and the moving speed is adjusted. Can be changed.

Embodiment 2. FIG.
The second embodiment is different from the first embodiment in the configuration of the drive circuit. Note that portions similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
FIG. 15 is a circuit diagram showing the drive circuit 7A of the second embodiment. As shown in the figure, the drive circuit 7A is substantially the same as the drive circuit 7 of the first embodiment, but is connected in series with the drive coils 34A and 34B and is a resistor that limits the current flowing through the drive coils 34A and 34B. 79A, 79B, and short-circuit switches 80A, 80B connected in parallel to the resistors 79A, 79B and bypassing the resistors 79A, 79B. The resistor 77 provided in the drive circuit 7 of the first embodiment is not provided in the drive circuit 7A of the second embodiment.
In such a drive circuit 7A, in the case of a closing operation, the short-circuit switches 80A and 80B are turned on to bypass the resistors 79A and 79B, and an exciting current is caused to flow through the drive coils 34A and 34B. In the open operation, the currents flowing through the drive coils 34A and 34B via the resistors 79A and 79B are controlled by turning off the short-circuit switches 80A and 80B.

  As described above, the second embodiment has the same effect as that of the first embodiment, and includes a resistor in series with each drive coil and a short-circuit switch in parallel with each resistor. Accordingly, the current flowing through each drive coil can be adjusted, and the opening speed can be changed more flexibly.

Embodiment 3 FIG.
The third embodiment is different from the first embodiment in the configuration of the drive coil and the drive circuit. Note that portions similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
FIG. 16 is a schematic diagram for explaining the configuration of the electromagnetic actuator 3A according to the third embodiment. As shown in the figure, in the electromagnetic actuator 3 </ b> A, a first drive coil 37 and a second drive coil 38 are disposed in the inner space of the stator 31 along the moving direction of the mover 32. Each drive coil 37, 38 is wound twice, the first drive coil 37 is composed of coils 37A, 37B, and the second drive coil 38 is composed of coils 38A, 38B.
Since each of the drive coils 37 and 38 is composed of two drive coils 37A and 37B and 38A and 38B in this way, the drive circuit 7B that supplies the excitation current to each of the drive coils 37 and 38 is a circuit for making an operation. And a circuit for opening operation can be separated.

FIG. 17 shows a circuit for the making operation, and the first drive coil 37A and the second drive coil 38A are connected. During the turning-on operation, the discharge switch 72A is turned on to discharge the current from the charged capacitor 71A, thereby exciting the drive coils 37A and 38A.
FIG. 18 shows a circuit for an opening operation, and the first drive coil 37B and the second drive coil 38B are connected. During the opening operation, by turning on the discharge switch 72B, a current is discharged from the charged capacitor 71B, and the drive coils 37B and 38B are excited. Changeover switches 81a and 81b are provided between the drive coils 37B and 38B, and the drive coils 37B and 38B to be excited are selected by turning ON / OFF the changeover switches 81a and 81b.

  As described above, the third embodiment has the same effects as those of the first embodiment, and since the number of switch switches is small, the switching operation is simple and the time required for switching can be shortened. it can. In addition, the amount of magnetic flux generated from each drive coil during each operation can be adjusted by changing the number of turns of the drive coil used during the closing operation and the drive coil used during the opening operation, eliminating the need for a current limiting resistor. is there.

In addition, as another example of the third embodiment, a configuration in which a tap is provided in the middle of the winding of each drive coil 370, 380 instead of the configuration in which each of the above-described drive coils 37, 38 is wound twice is described below. explain.
The drive coils 370 and 380 of another example of the third embodiment can be divided into drive coils 370A and 370B and 380A and 380B by providing the taps 370C and 380C.
The drive circuit 7C in this case is shown in FIG. The configuration of the drive circuit 7C is substantially the same as that of the drive circuit 7 of the first embodiment (see FIG. 3), but the negative terminal of the capacitor 71B used during the opening operation is connected to the taps 370C and 380C. As a result, the current from the capacitor 71B excites the drive coils 370B and 380B, which are part of the drive coils 370 and 380. Note that, during the closing operation, the entire drive coils 370 and 380 are excited by the capacitor 71A as in the first embodiment.
With such a configuration, the number of turns of the drive coil to be excited can be changed during the opening operation and the closing operation, and the change of the number of turns can be freely set depending on the position of the tap. Therefore, the amount of magnetic flux generated from each drive coil during each operation can be easily adjusted.

1 Circuit breaker (switching device), 3, 3A electromagnetic actuator, 4 insulator,
5 Contact pressure spring, 6 Operation rod, 7, 7A, 7B, 7C Drive circuit, 8 Control circuit,
22 fixed contact, 23 movable contact, 31 stator, 32 mover, 33 release spring,
34, 34A, 34B Driving coil, 35 magnetic pole, 36 permanent magnet,
37A, 37B, 38A, 38B drive coil,
73a, 73b, 74a, 74b, 75a, 75b changeover switch,
79A, 79B resistance, 80A, 80B short-circuit switch,
370A, 370B, 380A, 380B Drive coil, 370C, 380C Tap.

Claims (11)

In an electromagnetically operated electromagnetic actuator that reciprocates between two positions of opening and closing,
A stator, a mover disposed in a reciprocating manner in the inner space of the stator, an open spring for biasing the mover in a direction away from the stator, and an inner space of the stator A plurality of drive coils arranged along the moving direction of the mover for driving the mover, a drive circuit for supplying an excitation current to each drive coil, and the mover on the stator side With a permanent magnet to attract and hold,
By selecting the excitation direction and the drive coil to be excited from among the drive coils, the magnetic flux generated by the drive coil is made larger during the low-speed release operation than during the high-speed release operation, so that the stator and the movable An electromagnetic actuator characterized by increasing the magnetic attraction force with the child . The electromagnetic actuator according to claim 1, wherein a magnetic pole portion formed so as to protrude from the stator is disposed between the drive coils arranged adjacent to each other. A contact pair consisting of a fixed contact and a movable contact that can be contacted and separated, an electromagnetic actuator that opens and closes the contact pair via an operating rod, and the contact pair that is disposed on the operating rod and insulates the electromagnetic actuator An electromagnetically operated switching device for opening and closing a main circuit, comprising an insulator and a contact pressure spring disposed on the operation rod and applying a contact load to the contact pair,
The electromagnetic actuator according to claim 1 , wherein the electromagnetic actuator is an electromagnetic actuator according to claim 1 . The electromagnetic circuit according to claim 3, further comprising a control circuit that sends an operation command to the drive circuit, wherein the control circuit selects a drive coil to be excited based on a measurement result of a current or voltage of the main circuit. Operative switchgear. The drive coil has a tap in the middle of the winding, via the tap select a part of the driving coil, the electromagnetic according to claim 3 or claim 4 and supplying an excitation current Operative switchgear. The drive circuit includes a plurality of changeover switches for selecting a drive coil to be excited,
Each change-over switch is set for the next opening operation after the closing operation for closing the contact pair is completed, and is set for the next closing operation after the opening operation for opening the contact pair is completed. The electromagnetically operated switchgear according to any one of claims 3 to 5 , wherein the electromagnetically operated switchgear is provided. The drive circuit includes a resistor connected in series with the drive coils to limit a current flowing through the drive coils, and a short-circuit switch connected in parallel to the resistors and bypassing the resistors. The electromagnetically operated switchgear according to any one of claims 3 to 6 . A contact pair consisting of a fixed contact and a movable contact,
A stator made of a magnetic material; a mover disposed in a reciprocating manner in the inner space of the stator; an open spring that biases the mover in a direction away from the stator; and the stator A plurality of drive coils arranged along the moving direction of the mover for driving the mover, a drive circuit for supplying an excitation current to the drive coils, and a drive circuit for the drive coils. A magnetic pole portion disposed between and projecting from the stator; and a permanent magnet that attracts and holds the movable element on the stator side, and is driven in a reciprocating manner between two positions of opening and closing. Electromagnetically operated electromagnetic actuator,
And an operating rod for connecting the contact pair and the electromagnetic actuator,
A method for controlling an electromagnetically operated switchgear for opening and closing a main circuit comprising:
By selecting the excitation direction and the drive coil to be excited from among the drive coils, the magnetic flux generated by the drive coil is made larger during the low-speed release operation than during the high-speed release operation, so that the stator and the movable A control method for an electromagnetically operated switchgear, characterized in that control is performed so as to increase a magnetic attractive force with a child . 9. The electromagnetic circuit according to claim 8, further comprising a control circuit that sends an operation command to the drive circuit, wherein the control circuit selects a drive coil to be excited based on a measurement result of a current or voltage of the main circuit. Control method for operation type switchgear. When performing the closing operation to close the contact pair, all the driving coils are excited in the forward direction, and when performing the high speed opening operation to open the contact pair at high speed, When the drive coil disposed at the end on the closing direction side is excited in the reverse direction and the contact pair is opened at a low speed, the drive disposed at the end on the closing direction side of the mover is performed. The method for controlling an electromagnetically operated switchgear according to claim 8 or 9, wherein two or more drive coils including the coil are excited in opposite directions. The drive coil to be excited is selected by a plurality of changeover switches provided in the drive circuit. After the closing operation is completed, each changeover switch is set to ON / OFF in preparation for the next release operation. The control of an electromagnetically operated switchgear according to any one of claims 8 to 10 , wherein after the completion of the operation, each of the changeover switches is set to ON / OFF in preparation for the next closing operation. Method.

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